1. Field of the Invention
The present invention relates to a golf club head having a variable loft angle, and more particularly, to a golf club head having a variable loft angle that is designed to rotate thereby to allow selective variation of the loft angle of the club.
2. Background of the Related Art
There are no technical ideas related in the present invention that are conventionally known and therefore, an explanation of problems appearing in conventional golf clubs is given hereinafter.
Golf clubs traditionally comprise a number of woods, drivers, a number of irons, wedges, and putters, and they have somewhat different loft angles, according to the designs of a variety of companies. Generally, drivers have loft angles ranged between 5° and 13°, and woods have them ranged between 13° and 15°. A No.2 iron has a loft angle of 19°, a No.3 iron has a loft angle of 22°, a No.4 iron has a loft angle of 25°, a No.5 iron has a loft angle of 28°, a No.6 iron has a loft angle of 32°, a No.7 iron has a loft angle of 36°, a No.8 iron has a loft angle of 40°, and a No.9 iron has a loft angle of 44°. On the other hand, a pitching wedge has a loft angle of 48°, an approach wedge has a loft angle of 52° or 53°, a sand wedge has a loft angle of 55° or 56°, and a lob wedge has a loft angle of 60°.
A loft angle of a golf club is determined between a vertical plane of 90° formed at the front of a club face with respect to the ground line extended from a sole located at the front of the club face when a sole of the golf club is placed on the ground and a slant plane formed along the middle portion of the club face at which hitting a golf ball is executed. The loft angle is one of important considerations required when the golf club hits the ball. Thus, when the loft angle is large, the golf ball travels high, having a relatively short distance, and contrarily, when it is small, the ball travels low, having a relatively long distance.
However, all of conventional golf clubs have only one loft angle that is not variable because the club heads are undetachably fixed to shafts of the golf clubs. Thus, golfers should carry a full set of golf clubs adequate for various usage purposes. It is however inconvenient to carry the full set of golf clubs that is not used well, and even though the golfer has the full set of golf clubs, it is also not easy to change the golf clubs with another whenever required.